Boom arm



E. BAAS BOOM ARM Oct. 27, 1959 Original Filed Sept. 7, 1955 3 Sheets-Sheet 1 FIG. 6.

INVENTOR ERWIN BAAS.

ATTORNEY.

Oct. 27, 1959 Original Filed Sept. '7, 1955 E. BAAS BOOM ARM 3 Sheets-Sheet 2 FIG. IO.

INVENTOR ERWIN BAAS.

ATTORNEY.

Oct. 27, 1959 E. BAAS 2,910,190

' BOOM ARM Original Filed Sept. 7, 1955 3 Sheets-Sheet 5 INVENTOR ERWIN BAAS.

ATTORNEY.

United States Patent F BOOM ARM Erwin Baas, Hamburg-Hochkamp, Germany Original application September 7, 1955, Serial No. 532,993. Divided and this application October 30, 1956, Serial No. 619,154

Claims priority, application Germany May 12, '1955 3 Claims. (Cl. 212-144) The present invention relates to a boom arm in general and to such boom arm to be mounted at the front or rear end of a vehicle, as a tractor, in particular.

This is a divisional application of the copending patent application Serial No. 532,993, filed September 7, 1955.

It has been proposed before to provide loaders mounted on vehicles which comprise usually riveted or welded box carriers which are designed'in such manner that the cross section bearing the greatest strain has the greatest resist-' ance and which cross section is then tapered oif along the carrier in accordance with the stresses subjected thereto. The ends of such box carriers are equipped with reinforcements in the form of attachments, boxes, which are welded thereto, or the like, in order to provide for the attachment of crane hooks or for the incorporation of axles or the like. These known loaders require a comparatively long time for manufacture and cannot be made in an economical manner.

It is, therefore, one object of the present invention to provide a boom arm which avoids the drawbacks of the known structures.

It is another object of the present invention to provide a loader, the boom arm of which is formed of one or a plurality of beams which are pressed flat in their center portion crosswise to the direction of the stresses and which are at their ends folded to the inside towards the center thereof. The two booms which are formed of hollow beams are connected together by particularly provided cross members. Since the starting material for the loader is a cylindrically or conically shaped tube into which the flat pressing and folding is worked, a fast and economical manufacture is presented and the inwardly directed fold at the ends of the tube brings about automatically a reinforcement, thereby eliminating additional attachment normally required to achieve this end and simultaneously providing a manufacture.

It is still another object of the present invention to provide a loader comprising a hollow beam which is provided with brackets, supports, braces or the like for connection with pneumatic or hydraulic cylinders, thereby providing means for up and down motion or for a rotating motion of the lift arm.

It is yet another object of the present invention to provide a loader :which comprises a beam the ends of which are folded to the inside towards the center thereof which are adapted to receive bearing supports for the lift arm on one hand and on the other hand a reinforced and stitf end for fitting a crane hook, a grab support or a hook for implements or the like.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

Figure 1 is a side elevational view of a hoist provided with a beam designed in accordance with the present invention;

Fig. 2 is a top plan view of the beam shown in Fig. 1;

still more economical 2,910,190 Patented Oct. 27, 1959 2 3 is a section along the lines 3--3 of Fig. 1; 4 is a section along the lines 4--4 of Fig. 1; 5 is a section along the lines 55 of Fig. 1; 6 is a section along the lines 66 of Fig. l; 7 isa section along the lines 7-7 of Fig. 1; Fig. 8 is a section along the lines 88 of Fig. 1;

. Fig. 9 is a side elevational view of a tractor with a frontend loader made of beams in'accordance with the present invention;

Fig. 10 is a plan view of the tractor shown in Fig. 9;

Fig. 11 is a side elevational view of a tractor witha second embodiment of a front-end loader; and

Fig. 12 is a side elevational view of a tractor with a third embodiment of a front-end loader.

Referring now to the drawings, the beam applied to the loader designed in accordance with the present invention is made in accordance with a method disclosed in the copending patent application Serial No. 532,993. The beam 1 is curved in longitudinal direction. It is pivotally joined on a pivot 2 of a supporting column 3. At its free end of narrow cross section the beam 1 is provided with a load hook 4. A hearing bracket 5 is welded to the concave sideof the curved beam 1. The outer end of a piston 6 of a hydraulic cylinder 7 is secured to the Fig. Fig. Fig. Fig. Fig.

bracket 5 and the latter is in turn pivotally mounted by 7 as a support and as a welding base for the bearing bushing 12 of the beam 1.

The zone of highest stress is. in the area marked by the section lines 6-6. At this point the beam 1 is flattened only crosswise to the direction of the vertical stresses exerted thereto, so that the greatest moment of resistance is brought about.

The loader designed'in accordance with the present invention and shown in Figs. 9 to 12 is disclosed as a front-end loader in connection with a tractor. Two beams 1, 1 and 1 respectively, are used in each instance in these structures, the shape of said beams being designed in accordance with the showing in Figs. 1 to 8. Cross bars 13 and braces 14 (Fig. 10) are welded to each pair of Said beams to form a rigid loader frame, the front end of which is equipped with hooks or bearings 15', 15 and .15 respectively, in the embodiments shown in Figs. 9, 11 and 12 in order to receive conventional front-end loader equipment devices 16, 16 and 16 respectively.

The rear end of the loader frame rests in brackets 17 17 and 17 respectively, which are laterally secured on the chassis 18, 18 and 18 respectively, of a tractor 19', 19 and 19 respectively. The loader frame is rotatably mounted upon a pivot 20', 20 and 20 respectively, and is operated by the hydraulic device 21', 22', 21 22 21 and 22 respectively. The hydraulic cylinders 21', 21 and 2.1 respectively, are pivotally mounted on the pins 23', 23 and 23 respectively, of the chassis 18, 18 and 18 respectively, while the pistons 22', 22 and 22 respectively, reciprocating in the cylinders 21, 2.1 and 21 respectively, are secured at their free ends to the pin 24', which in the embodiment shown in Fig. 9 is mounted in the beam 1. The chassis 18', may form a closed unit with the brackets 17', the hydraulic device 21 and 22' and the beams 1, as shown in Figs. 9 and 10, which aggregate is easily exchangeable on the chassis or running gear of the tractor.

The downward bending of the beam 1 which forms the loader brings about the advantage that the loader reaches the ground over the front wheels of the tractor with the least space requirement and with a little space requiring hydraulic device.

Two additional embodiments of a front-end loader mounted on a tractor are disclosed in Figs. 11 and 12. In both these embodiments the hydraulic cylinder 21 and 21 respectively, is of greater length compared with that in the embodiment shown in 'Fig. '9 and accordingly a longer piston 22 and 23 is likewise provided. 'Otherwise the structure is substantially identical with that disclosed in Fig. 9.

In the embodiment shown in Fig. 12, however, the beam 1 is equipped with a frame'ZS which carries in this structure the pivot 24 for securing the free end of the piston'22 thereto.

While the embodiment shown in Fig. '12Jfo'llows substantially the embodiment disclosed in Fig. 9 of the drawings, the beam 1 has fitted thereto a girder 27 which extends upwardly and which is equipped with aplurality of bores 28 "the latter being adapted to receive selectively the pivot 24 for securing the free end of the piston 22 By selecting different bores 28 the swinging radius of the loader may be varied and accommodated to the desired working conditions. 'The beams I are likewise downwardly curved in this embodiment and are also of the same design as shown in Figs. 1 to 8.

It is to be understood that the loader may be used for any other purposes than for lifting tractor auxiliary devices and its use is not limited to front-end loaders. The present device isjhowever, particularly suitable and brings about appreciable advantages in connection withiloaders for tractors due to the novelbeam design.

While I have disclosed several embodiments of the present invention, it is to be understood that these emb'odiments are given'by example only and not in a limiting sense, the scope of the present invention being determined by'the objects and the claims.

I claim:

'1. A'boom arm "for a loading device of a vehicle comprising an integral longitudinal hollow beam having fiattened side portions connected by rounded portions, said side portions being disposed in a plane parallel to the plane in which said boom arm swings during lifting and extending substantially along the full length of said boom arm, in order to increase its resistance against bending, and having a folded-in portion projecting inwardly towards the longitudinal axis of said beam at its ends, and said folded-in portion merging with said rounded portions at its ends in order to provide a plurality of substantially parallel sheets formed by said folded-in portion jointly with said flattened side portions for the connection of bearing members and to increase the resistance moment against-cracking, turning and shearing at the ends of said beam.

2. The boom arm, as set forth in claim 1, wherein said hollow beam is downwardly curved towards its free end.

3. Ike boom arm, as set forth 'in claim l, which includes at least one cross-bar projecting laterally from said beam and adapted to 'be-securcd to another hollow beam.

References Cited in the file of this ,patent UNITED STATES PATENTS 1,255,841 Adams Feb. 12, 1918 1,974,458 Hallquist Sept. 25, 1934 1,983,074 Du-rell Dec. 4, 1934 2,077,454 Almda'le Apr. 20, 1937 2,528,588 Forslund Nov. 7, 1950 2,581,731 Terry Jan. 8, 1952 2,610,754 Inskeep Sept. 16, 1952 2,672,994 Werner Mar. 23, 1954 FOREIGN PATENTS 722,517 Great Britain Jan. 26, 1955 819,065 Germany Aug. 4, 1952 

